Expression of mRNA for chemokines and myeloid colony stimulation factors in the tumor of WT and CCR2^−/− mice. 3LL tumors were resected from WT or CCR2^−/− mice on days 7 and 14 after tumor inoculation, and the expression of mRNA for chemokines (A) and myeloid colony stimulation factors (B) was analyzed by RT-PCR. Graph represents the mean (± SD) of four mice. *P < .05; **P < .01. Data are representative of 2 independent experiments.